Catalysts for co2 hydrogenation

Abstract

Embodiments of the present disclosure describe methods of preparing pre-catalysts that may be activated under methane to form catalysts for the hydrogenation of carbon dioxide to form olefins, among other chemical species. Embodiments of the present disclosure also describe methods of preparing catalysts and pre-catalysts, catalyst and pre-catalyst compositions, and methods of producing one or more chemical species using catalysts.

1 . A method of preparing a catalyst, comprising:
 grinding one or more of a metal precursor, a promoter precursor, and a support precursor to form a mixture;   calcining the mixture at one or more temperatures to form a pre-catalyst; and   flowing methane over the pre-catalyst to form a catalyst active in the production of olefins via CO 2  hydrogenation.   
     
     
         2 . The method of  claim 1 , wherein the metal precursor includes one or more of iron, cobalt, and nickel. 
     
     
         3 . The method of  claim 1 , wherein the metal precursor includes one or more of a metal oxide, metal hydroxide, metal nitrate, metal oxalate, metal chloride, metal carbonyl, and metal sulphate. 
     
     
         4 . The method of  claim 1 , wherein the promoter precursor includes one or more of an alkali metal and alkaline earth metal. 
     
     
         5 . The method of  claim 1 , wherein the promoter precursor includes one or more of sodium, calcium, potassium, caesium, manganese, copper, lithium, rubidium, francium, beryllium, magnesium, strontium, barium, and radium. 
     
     
         6 . The method of  claim 1 , wherein the support precursor includes one or more of aluminum, titanium, zirconium, silicon, magnesium, carbon, carbon nanotubes, graphene, zinc, and zeolites. 
     
     
         7 . The method of  claim 1 , wherein the metal precursor, promoter precursor, and support precursor are each salts, wherein an anion of the salt is nitrate. 
     
     
         8 . The method of  claim 1 , wherein the metal precursor, promoter precursor, and support precursor mixture is fused. 
     
     
         9 . The method of  claim 1 , wherein the one or more temperatures range from about 350° C. to about 450° C. 
     
     
         10 . The method of  claim 1 , further comprising reducing a grain size of the pre-catalyst. 
     
     
         11 . The method of  claim 1 , wherein the grain size ranges from about 25 μm to about 500 μm. 
     
     
         12 . The method of  claim 1 , wherein the catalyst includes a metal content ranging from about 10 wt. % to 100 wt. %, a promoter content ranging from about 0 wt. % to about 20 wt. %, and a support content ranging from about 0 wt. % to about 90 wt. %. 
     
     
         13 . The method of  claim 1 , the methane and methane/hydrogen mixture reduces metal oxides to metallic metals and provides a carbon source for forming metal carbides. 
     
     
         14 . The method of  claim 1 , the methane/hydrogen mixture and natural gas also can use a source for forming metal carbides. 
     
     
         15 . The method of  claim 1 , wherein the one or more temperatures range from about 500° C. to about 1000° C., and at a pressure is about 1 bar to 20 bar for a period of 1 min to 1 hour. 
     
     
         16 . The method of  claim 1 , wherein the catalyst is supported on one or more of Al 2 O 3 , SiO 2 , TiO 2 , ZrO 2 , MgO, carbon, carbon nanotubes, and graphene. 
     
     
         17 . A method of preparing a catalyst, comprising:
 grinding one or more of Fe(NO 3 ) 3 .9H 2 O, Na(NO 3 ) 3 , and Al(NO 3 ) 3 .9H 2 O to form a homogenous powder mixture;   calcining under static air at or to one or more of a first temperature and a second temperature; and   flowing methane over the pre-catalyst to form the catalyst.   
     
     
         18 . A method of producing chemical species, comprising:
 flowing at least carbon dioxide and hydrogen over a methane or methane/hydrogen mixture or natural gas activated catalyst to produce hydrocarbons by CO 2  hydrogenation.   
     
     
         19 . The method of  claim 18 , where in the temperature range from 150 and 450° C., and the space velocity range between about 5 and about 100 lit/g cat ·h. 
     
     
         20 . The method of  claim 18 , wherein the hydrocarbons include one or more straight chain C 2  to C 9  olefins.